choochiegirl

i know i should not really even worry about water changes, still cycling and only on day 4, but I like to be prepared. I have a 30 gallon tank that is cycling fish less. I have read, that once my ammonia & nitrites are 0 and my nitrates go up, to do a water change then add my fish. i have seen some say 20-25% water change. So really how do i decide how much water that is?? I am horrible at math. Do i figure out my tank volume and take 20-25 % of that?? the thought of math kills me. If i think i am doing this right, it would be 6-7.5 gallons to remove?? and of course the bucket i bought does not have measurements on it, it just shows 1-12 inside, but does not say 12 what.

bbfeckawitts

Hi Choochiegirl,
What you need to do is test your NitrAtes when the cycle is done. Lets say your Nitrates are 20ppm. You would need to do a 50% water change (15 gallons) (or more) to bring the Nitrates to 10. If your Nitrates were 30, you would need to change 2/3rds of your water to get your nitrates to 10. Which would be 20 gallons.

Aim to get it to 10 before adding fish, then keep it under 40 for hardier fish (regular water changes), and under 20 (more frequent water changes) for more delicate fish. As long as you don't overstock (or have messy fish like plecos) a once every two weeks water change of 25-50% (depending on your nitrate level, which you should check every week) will probably keep it low. However, with messy fish like plecos, or large fish like Oscars, you will need to do more frequent large water changes, like 50% every week.

But you don't know EXACTLY how much water to change until you test, so it may be less than what I put up there, you just never know.

Good luck with your tank, glad to see you knew about cycling BEFORE adding fish, I didn't, but the people here advised me on the best course of action, but it was too late for my tiger barbs. All my fish are doing perfectly, but I am overstocked, so I have to do 50% water changes once a week. Brianna

choochiegirl

thanks for your answer. I've been thinking about it now, once I'm ready to change my water for the first time, I will test before and after and if it's still high. I can always change again right away, can't I?

If I add plants at this time (water change time), will moving the gravel around mess with the cycle?

Also once it's cycled & running and fishy, I have read to only partially vac the gravel, should i only do certain areas every week? as-in divide it in quarters and do a different quarter every week?

vin

Look at it this way....10% of 30g is 3 gallons....so 20% is 6g, 30% would be 9g, 40% is 12g, 50% is 15g and so on. Each additional 3g is another 10%.....Changing 1/3 of your water would be changing approx. 10g......Changing 2/3 of your water would be changing about 20g

Keeping your nitrates below 20 should be what your looking to do...Of course lower is always better.

bbfeckawitts

Hi Again, Yes you can always change it again if you need to. Just remember to wait a few hours after putting the water back to test, it is best to wait overnight though, just to be sure. Moving the Gravel around while adding plants should not huirt it one bit as most of the good bacteria lives in your filter. When I vacuum, I do 1/2 my tank, then the other half in 2 weeks, and have had no problems. No ammonia spikes/mini cycles. I test Ammonia/Nitrite/Nitrate every week, and you should make that a habit too. It determines how often you should make water changes, and if you need to do one sooner than planned. Good luck with your tank and fish. Brianna